17235. As used in this part, "switchblade knife" means a knife having the appearance of a pocketknife and includes a spring-blade knife, snap-blade knife, gravity knife, or any other similar type knife, the blade or blades of which are two or more inches in length and which can be released automatically by a flick of a button, pressure on the handle, flip of the wrist or other mechanical device, or is released by the weight of the blade or by any type of mechanism whatsoever. "Switchblade knife" does not include a knife that opens with one hand utilizing thumb pressure applied solely to
the blade of the knife or a thumb stud attached to the blade, provided that the knife has a detent or other mechanism that provides resistance that must be overcome in opening the blade, or that biases the blade back toward its closed position.
21510. Every person who does any of the following with a switchblade knife having a blade two or more inches in length is guilty of a misdemeanor:
(a) Possesses the knife in the passenger's or driver's area of any motor vehicle in any public place or place open to the public.
(b) Carries the knife upon the person.
(c) Sells, offers for sale, exposes for sale, loans, transfers, or gives the knife to any other person.
21590. The unlawful possession or carrying of any switchblade knife, as provided in Section 21510, is a nuisance and is subject to Sections 18000 and 18005. (18000 and 18005 cover sale or disposal of confiscated weapons)